The present invention relates generally to a latch guard used to secure a door latching mechanism from tampering. More particularly, the present invention relates to an improved latch guard that can be easily installed on the face of the door on which the latching mechanism is secured.
Conventional door locking mechanisms typically utilize a retractable spring-loaded latch operated by a door knob. When the door is closed, the latch contacts a strike plate causing the latch to recede within the door until it is aligned with a recess formed within the door frame or jamb. Once the latch is aligned, the latch springs into the recess in the door jamb or frame. The latch can be retracted out of the recess in the door jamb using a door knob or handle so as to open the door.
A problem with door and door latching mechanisms is that they can be easily violated. For example, a latch can be disengaged from the recess in the door jamb and the door opened by sliding a credit card or similar flexible material between the door jamb and door. The latch might alternatively be disengaged from the recess in the door jamb by inserting rigid objects such as screwdrivers and crowbars in the gap between the door and the door jamb. Thus, there is a problem in the art of unwanted tampering with door latching mechanisms.
There have been several attempts made to address this problem. U.S. Pat. No. 5,415,020 (""020 Patent) entitled xe2x80x9cLatch Guard for Outwardly Opening Doorsxe2x80x9d and U.S. Pat. No. 5,547,239 (""239 Patent) entitled xe2x80x9cLatch Guard For Center Hung Doorsxe2x80x9d disclose latch guards for protecting against tampering with a door""s latching mechanism. FIG. 1 provides a view of a latch guard with features in accordance with those of the ""020 and ""239 Patents. Both the ""020 and ""239 Patents purport to address the problem of tampering with the latching mechanism by attaching a plate of some sort to the front of the exterior door face.
The plate bridges the gap between the door to which the plate is attached and either an opposing door or door frame. The latch guard operates to impede a prospective intruder from inserting a foreign device between the door and the door jamb or between two adjoining doors for purposes of tampering with the door latch.
Of course, there are problems associated with latch guards such as those disclosed in the ""020 and ""239 Patents. Latch guards in accordance with those disclosed in the ""020 and ""239 Patents are secured to the door on the exterior portion of the door. In most instances doors are not reinforced in these areas. In addition, because the mechanism by which the latch guard is secured to the door is accessible to would be intruders, the latch guard can be removed so as to provide access to the door latching mechanism. Further, such latch guards must be sufficiently wide to cover the gap between a door and door jamb. However, as a consequence, when the door opens, the latch guard extends beyond the edge of the door to which it is attached. The overlapping latch guard may catch and thereby damage people""s clothing as they walk past the open door. Additionally, it may not be aesthetically pleasing to have a latch guard mounted on the exterior surface of a door.
Accordingly, a primary goal of the present invention is to provide a latch guard that is secure against unauthorized removal, does not significantly overlap the edge of a door, and does not detract from the door""s aesthetics.
A latch guard in accordance with the present invention addresses these and other shortcomings in the art. According to one aspect of the invention there is provided a latch bolt guard assembly for protecting a latch bolt of a door from tampering. The door has a surface for attachment thereto of a latch bolt assembly, which surface faces an interior surface of a door jamb when the door is in the closed position. The latch bolt guard assembly comprises the following elements: a latch bolt tumbler assembly; a face plate integrally formed with the latch bolt tumbler; and a protection bar integrally formed with the face plate. The protection bar substantially fills a gap between the door and the door jamb as viewed from an exterior side of the door when the door is in a closed position. The face plate may have a receptacle therein through which a latch bolt extends. The face plate may have holes therein for securing the assembly to the door.
According to another aspect of the invention, there is disclosed a latch bolt guard system for application to a door and door jamb combination. The latch bolt guard system comprises a latch guard and a strike plate. The latch guard has a face plate for attaching the latch guard to the door, and a protection bar attached to the face plate. The protection bar substantially fills a gap between the door and the door jamb as viewed from an exterior side of the door when the door is in a closed position. The strike plate has a first securing area and a second securing area with a latch strike surface disposed there between. The latch strike surface is offset relative to the first securing area and the second securing area so as to form a recess. When the strike plate is attached to the door frame and the door is closed upon the door frame, the face plate aligns with the latch strike surface and the face plate is accommodated by the recess.
According to another aspect of the invention, there is disclosed a latch bolt protection system for application to a door. The latch bolt protection system comprises a latch bolt assembly and a latch guard. The latch bolt assembly has a latch bolt assembly face plate, wherein the latch bolt assembly is countersunk into the surface of the door so that the latch bolt assembly face plate is offset into the door away from the surface of the door. The latch guard has a guard face plate for attaching the latch guard over the latch bolt assembly face plate, and a protection bar integrally formed with the latch guard face plate. The guard face plate is smaller than the latch bolt assembly face plate so that the latch guard face plate can be applied over the latch bolt assembly face plate. The latch guard face plate aligns flush with an exterior surface of the door.
Other features of the present invention are described below.